Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a material that uses carbon nanotubes to create a flexible backplane for an artificial electronic skin (e-skin).
“With our solution-based processing technology, we have produced mechanically flexible and stretchable active-matrix backplanes, based on fully passivated and highly uniform arrays of thin film transistors made from single walled carbon nanotubes that evenly cover areas of approximately 56 square centimeters,” says Ali Javey, a faculty scientist in Berkeley Lab’s Materials Sciences Division and a professor of electrical engineering and computer science at the University of California (UC) Berkeley in Berkeley Lab press release. “This technology, in combination with inkjet printing of metal contacts, should provide lithography-free fabrication of low-cost flexible and stretchable electronics in the future.”
It seems carbon nanotubes and artificial skin is becoming a popular research area as researchers at nearby Stanford University also looked at how carbon nanotubes could be used in flexible electronics and started demonstrating the usefulness of the method with an artificial skin.
Javey and his colleagues have published their work in the ACS journal Nano Letters in a paper entitled “Carbon Nanotube Active-Matrix Backplanes for Conformal Electronics and Sensors”.
Curiously the researchers bemoan the general problem that has existed in this are of flexible electronics of not being able to attain a pure single-walled carbon nanotube (SWNT) solution to create your flexible electronic devices. I say curious because Zhenan Bao—the same researcher at Stanford who developed the artificial skin—also developed in cooperation with researchers from the University of California Davis a method by which to come up with the exact mix of SWNTs you want.
In the Berkeley Lab press release it is made clear that the researchers used “a SWNT solution enriched to be 99-percent semiconductor tubes”, but it doesn’t indicate how they were able to get that level of purity. Maybe they can give Bao a shout out and try and use her method.
In any case, it will be interesting to see if the two research groups can move this initial work that uses artificial skin as a demonstration of the methods into broader uses for furthering the development of flexible electronics.
Dexter Johnson is a contributing editor at IEEE Spectrum, with a focus on nanotechnology.